Especially for intelligent individual luminaires (e.g. standard luminaires), an automatic daylight- and presence-dependent light control is increasingly being stipulated in specifications. Reasons for this include increased convenience demands, in the form of a constant illuminance on the work surface, with at the same time more restrictive stipulations for the maximum energy consumption. The German energy saving regulations (ENEV) and the European Energy Performance of Buildings Directive (EPBD) shall be mentioned here. Increasingly simple and cost-effective solutions are therefore being demanded. This means, inter alia, that the function of daylight regulation and presence detection should be realized with the fewest possible components. Like all electronic devices, said components require an energy supply that is efficient enough to ensure a low standby power consumption of the overall solution.
LED technology not only makes it possible to develop ever more efficient luminaires, but offers new freedoms of design. This freedom of design arises not just from the possibility of flexibly arranging the individual LEDs on freely configurable circuit board shapes/circuit board formats, but also, in particular, from the small structural height of the LED modules. The limitation of the minimum luminaire structural height that can be realized is currently determined solely by the structural height of the LED driver and of the light control components to be integrated into the luminaire.
To summarize, the lighting industry is thus confronted with two problems to be solved simultaneously: firstly, the need for simple, cost-effective daylight- and presence-dependent light control solutions consisting of the fewest possible components. Secondly, the structural height of the components used ought to be as small as possible, with a permanent efficient energy supply being required at the same time.
The solutions that have been commercially available hitherto are oriented toward the de facto standard structural height of the LED drivers of 21 mm. In general, the solutions for individual luminaires consist of one or a plurality of dimmable LED drivers, a control device and at least one light/presence sensor.
In already optimized/simplified systems, the control device is obviated; this function is performed by either the sensor or alternatively the LED driver itself. For these systems there are two solutions for the connection of the sensor:
a) Connection of the sensor via the existing digital addressable lighting interface (DALI) of the driver. For this purpose, either the normally passive DALI interface of the driver has to be modified to form an active DALI interface, which supplies a DALI current for the supply of external components, or a DALI power supply unit has to be integrated into the sensor. Disadvantages include, firstly, a higher outlay on component parts and, secondly, a higher standby power.
b) The LED driver has an additional interface for the sensor connection. The main disadvantage is the higher outlay on component parts, and the additional terminals.